Circuit controlling altimeter



p 9, 1952 o. s. FIELD ETAL CIRCUIT CONTROLLING ALTIMETER Original Filed July 29, 1944 2 SI-IEETS SHEET 1 7776/) Gttorneg Sept. 9, 1952 o D ETAL 2,609,684

CIRCUIT CONTROLLING ALTIMEITER Jriginal Filed July 29, 1944 2 SHEETS-SHEET 2 FIQZC.

ISnnentors The/)- attorney Patented Sept. 9, 1952 CIRCUIT CONTROLLING ALTIMETER Oscar s. Field and Sedgwick N. Wight, Rochester, N. Y., assignors to General Railway Signal Company,Ro chester, N. Y.

Originalapplication July'29, 1944, Serial No.

547,175. Divided and this application November 12, 1947, Serial No. 785,398

6 Claims. 1

This inventionflrelates to airway trafflc signalling systems, and-more particularly pertains to a contact mechanism controlled in accordance with the altitude of an airplane for use in such systems.

The contact mechanism of the present invention is more particularly useful in an airway trafiic signalling system in which airway trafiic conditions in advance are indicated in the cab of an airplane automatically irrespective of weather and fog conditions such as shown in the parent application Ser. No. 547,175, filed July 29, 1944, now Patent No. 2,458,361, issued January 4, 1949. In other words, this application is a division as to the structural features of a contact mechanism for use in a complete signalling system such as shown in the parent application,

which parent application is to be considered as i an improvement Over the prior applications of Wight et al., Ser. No. 517,814, filed January 11, 1944, now Patent No. 2,463,094, issued March 1, 1949, and Dicke Ser. No. 532,181, filed April 21, 1944, nowPatent No. 2,439,846, issued April 20, 1948.

One :of the objects of thepresent invention resides in the provision of means for operating a contact mechanism for manifesting an altitude at which an airplane is flying. This contact mechanism is to manifest such altitude in conformity with the indicationgiven by a rather delicately designed altimeter. In accordance with this object of the present invention, it is proposed to employ a light beam which swings through an arc in accordance with the swing of an indicating point. in an altimeter and in the provision of means for operating contacts to a position correspondingto the position assumed by such, light beam .through the medium of a selenium cell, photoelectric cell, or other suitable light responsive apparatus.

Other objects, purposes and characteristic features of. the present invention will in part be described hereinafter and will in part be obvious from the accompanying drawings in which:

Fig. 1 illustrates conventionally an airplane equipped with airplane carried apparatus embodying the present invention; and r Figs. 2A, 2B, and 2C illustrate an altimeter controlled contact mechanism constituting'part of the airplane carried mechanism illustrated in Fig. 1.

Since the subject matter of this divisionaljapplication relates to the structure and interrelation of parts of an altitude controlled contact mechanism for use in an air traffic signalling system, it is believed expedient to briefly consider the other apparatus with which this mechanism is associated. in an airplane. For this purpose, reference may be made toFig. 1 of the drawings which shows the structure of the airplane carried apparatus.

STRUCTURE Airplane carried structure.-Referring to Fig. l of the drawings, it will be observed that an airplane IP2 has been illustrated equipped with suitable airplane carried radio communicating apparatus. Near the front of the airplane and constituting part of this apparatus is a scanning antenna SA which may be of any suitable construction but is preferably of a construction such as illustrated in the prior applications of Wight, Field and Saint, or Dicke, above referred to. This scanning antenna SA, illustrated conventionally as a directional antenna supported at right angles on ascanning shaft, is connected through the medium ofa scanning receiver SAR, to suitable filtering apparatus FSI, and altimeter controlled contacts and a push button PB, to a kinescope including a screen S. By reference to the copending applications of Wight, Field and Saint, or Dicke, just referred to, it will be readily understood that this screen S will have displayed thereon pictorially each of the active ground radio transmitting stations in advance of the airplane within radio communicating distance, and juxtaposed thereon in substantially the same relation to each other as they are located in the field. It should be understood that the filter portions F2 and F3 of the filter FSI are constructed to admit only received radio energy characteristic of the altitudes 2 and 3, respectively. The particular characteristicjfrequency is then selected by the contact 20 of the altitude contact mechanism AC, as more specifically shown in Figs. 2A, 2B and 2C of the drawings.

This receiving apparatus also includes a hand knob HK which may be manually operated by the pilot, and by the use of which, the pilot may observe trailic conditions in advance in other altitudes than the particular altitude at which he isflying. It will be observed that the contact 29 controlled by the altimeter contactor AC isshown in the position 2 where it selects the filter portion F2 of the filter FSI which signifies that the airplane IPZ is flying at altitude 2000 as a result of which there is indicated on the screen S traffic conditions in ad- Vance of this airplane IPZ for altitude 2009. If now the pilot operates his hand knob HK to the 3 position, signifying an altitude of 3000 feet,

and if he then depresses the push button PB the screen S will be changed to indicate the same ground radio transmitting stations but with the spots identifying such stations flashing codes characteristic of those stations and also of traffic conditions in advance for altitude 3000. Similarly the contact 24 of the altimeter contactor I selects the filter portion 12 of the filter FPI so I that the airplane identifying code picked up by a antenna PA is one which was radiated from the same altitude 2000 which was presumably coded by the coder on thesame airplane and radiated from the tail antenna TA of the same airplane butoat a different carrierfrequency, and received by the same or a different carrier frequency as passed by receiver-SAR, it being re-- V the traffic conditions that normally exist, namely,

that there is at; [airplane approaching such fix withintwo blocks or sections in the rear for the altitude in question .(3000 foot altitude in the present. case). ltlj'shouldbe understood that even though a so-called normal radio beam may be emitted by ground station this ground station may. be potentially; clear (N followed by dotted G) or may be potentially hold (N followed by dotted R.) The filter .FPI is,.as above mentioned, provided. with filter. elements F12 and,

F13. The p'ortionsfof thefilter FSI identified by reference characters F2 "and F3 signify altitudes 2000 and 3000 feet respectively, whereas the tens numeral 1 of the characters FI2, Fl3, and so forth signifies that only radio energy shall pass therethrough whichiis characteristic of airplane identity for "these'altitudes but coded to V 5 identify the airplane'o'n which it originated and not coded to signify traffic conditions in advance in this same altitudel This radio energy is received through the medium of receiver PR and filter FPI. In this connection, it should be understood that each airplane is provided with a tail transmitter TT which emits radio energy of carrier frequency F modulated to an altitude frequency selected by the contact 2| and emitted through the medium of a rearwardly directed tail antenna TA. I

It will beobserved that this tail transmitter TI transmits energy of carrier frequency F and of an altitudejcharacter 2, 3 or 4 depending upon the position assumed by the contact 2| of the altitude contact mechanism AC. In other words,

provided. This receiver has an antenna element located in the held of the tail antenna TA. This check receiver GR. is provided with a filter FCI having associated filter elements F2, F3, etc. which are selected by the contact 22 of the altimcter contact mechanism AC. The {energy picked up" and selected by the particular filter element selected by the altimeter contact 22 may then flow through the relay W so as to cause this relayto followfthe code of the radio beam emitted rearwardly by the airplane 1P2. It will be observed that the filter elements Fl2 and FH of the filter rer constitute a second checking instrumentality and are connected one at a time 7 to therelay Yinaccordance with the position then assumed by'the contact 24 of the altimeter contactor AC. 7

From this consideration, it is readily under stood that the relay Wwill pick up and drop in accordance with the code transmitted locally by I the rearwardly directed tail antenna TA, whereas the relay Y will bob up and 'down in accordance with the radio "energy generated at a I ground radio transmittencoded in accordance with the coded tail transmitted energy received at the nextground station-in the..rear. These relays W and Y are provided with contacts-21 and 28 which are included in correspondence'circuits for the relay. 2.. Thisrelay Z is'rather quick acting and by reason of the fact. that the-two energizing i circuits for this relay Z pass through back contacts and front contacts respectively associated with the .movable" contacts Hand 28 of these relays, it is readily seen-that the relay Z will only assume its pickedup condition if the contacts 27 and 28 operate in perfect synchronism In this connection,it should be understood thatthe con- I tacts 21' and 28 are preferably make-before break when the airplane |P 2is flying at the 2000 foot In order'for the pilot to conveniently make a 7 continuous check as to the operativeness of his apparatus, a checking radio receiver CR has been and 28 will of course operate in perfectsynchronism if there are no other airplanes around, and.

if theairplane carried apparatus and the apparatus at both the firstgroundstation ahead and the first ground station in the rear are in proper working condition.

The :relay Z has associated therewith an indieating lamp'ZL which will be lighted only when this relay Z;:assumes its energized condition. Similarly, the relays W and Y have associated therewith lamps WL and YL, respectively, whichfor obviousreasons are lighted only'When-the I being understood; that :the correspondence bee tween the trans'mittedcocle and the received-code may be observed from the lamps 3| and 32 flashmg in synchronism. If the-relay Z 'is omitted for'this reason, the relays W and Y may also be I omitted in whichevent the lamps 3| and 32 alone will be relied upon for-the desired check informa-.

tion. V a

Although many of the devices illustrated in Fig. 1 have been shown rather conventionally, it is believed that this conventional showing is sufficient in view of the advanced status of the art in radio communication. It may, however, be pointed out that suitable generators are associated with the scanning antenna SA for the purpose. of generating voltages for application to the sweep plates of the kinescope including the screen S, and these generators have been specifically disclosed in the applications of Wight et al. and Dicke, above referred to. The letter F assigned to the filters FPI and FSI signify that the carrier frequency received by the scanning antenna receiver SAR is of carrier frequency f, Whereas the characters F2, F3, Fi2 and F13 signify four different kinds of modulating frequency superimposed on this carrier frequency ,1. As above pointed out two distinct carrier frequenciesmay be used. It may be pointed out that of these mod ulating frequencies the frequencies F2 and Fl2 have been assigned to altitude 2000, the frequencies F3 and F13 have been assigned to altitude 3000, and the frequencies F4 and FM would have been assigned to altitude 4000 if it had been illustrated. The modulating frequency generator FG associated with the tail transmitter TI is capable of generating current of carrier frequency F which is modulated at frequencies F2 or F3 depending upon the particular altitude 2000 or 3000 at which the airplane is flying as determined by altimeter contact 2| (Figs. 1, 2A and 2C). The filter FCI associated with the check receiver GR is of course constructed to receive carrier frequency F modulated at modulating frequencies F2 or F3 depending upon the position then assumed by the contact 22 of the altimeter contact mechanism AC. Both of the carrier frequencies F and 1 proposed to be employed in the present system are ultra-ultrashort-wave length frequencies in order that the antenna SA may be highly directional. The tail antenna TA preferably emits radio energy spread in a conical direction throughout an angle of substantially 90 whereas the individually focused radio antennae, four of which have been illustrated, of the scanning antenna SAwill only receive radio energy within very small spread of the focal axis of the particular receiving antenna focusing cup then effective. This angle of spread is preferably about two to five degrees.

Let us now refer to Figs. 2A and 2B of the drawings and observe the construction of the altimeter contact mechanism AC shown conventionally in Fig. 1 of the drawings and illustrated more specifically in Figs. 2A, 2B and 2C.

Referring to Fig. 2A, the altimeter contact mechanism includes a bellows or Sylphon SY which is evacuated and which has a collapsing tendency against the force of the spring 35 depending on the atmospheric pressure and therefore depending on the altitude at which the airplane is flying. This sylphon SY is held in a predetermined expanded condition depending upon the atmospheric pressure by a U-shaped spring 35 and is provided with an arm 36 which will sweep about the U-shaped part of the spring 35 as a pivot through an arc dependent upon the change in atmospheric pressure and will thereby, through the medium of the arm 36 and the link 31, rock the angle lever 38 supported for movement about a pin 39 so as to cause the arm 38 to pull or release the chain 4| against the tension of the hair spring 30, depending upon whether the atmospheric pressure is rising or falling respectively. As a result of this action, the pointer 45 is operated through the medium of the drum 44 in a clockwise direction if the atmospheric 6 pressureis falling (altitude increasing) and in a counter-clockwise direction when the atmospheric pressure is increasing (altitude decreasing); In other words, the altitude indicating pointer 45 is moved in a clockwise direction as the altitude of the airplane is increased.

In order to have the pointer 45 indicate the altitude accurately in spite of variations of the atmospheric pressure at sea level, the manually operable adjusting knob AK is provided to adjust the position of the dial plate 41. This dial plate 41 may be adjusted by the pilot in accordance with information received by him through the medium of radio communication, and may be adjusted to a positionto indicate with respect to a stationary pointer 34 the atmospheric pressure at sea level for. that particular locality. This turning of the manually operableknob AK, through the medium of the pinion 46, will rotate the toothed scale plate 41 with respect to which plate, the pointer 45 is read. In other words, if the knob AK is adjusted to indicate atmospheric pressure at sea level by pointer 34, the pointer 45 will indicate the altitude at which the airplane is flying under this atmospheric pressure condition. It is this latter construction that distinguishes the altimeter from a barometer. At the end of the shaft 43, on which the chain drum 44 and pointer 45 are supported, is provided a mirror MI for pur= poses presently to be described.

A suitable light source such as a lamp L is provided on the axis of the shaft 43 beyond the mirror MI. Between this lamp L and the mirror MI is provided a condensing lens CL which concentrates the light emitted by the lamp L intoa narrow beam striking the mirror MI at the point sub" stantially on the axis of the shaft 43. It is readily seen that by this construction the light beam re flected by the mirror MI will rotate in a plane at right angles to the axis of this shaft 43 and that this light beam will rotate in exact synchronism with rotation of the shaft 43. Adjacent this rotating light beam is provided a wheel rim 48 which supports two light responsive cells LCI and L02. These light responsive cells are included in the I circuits of relay DR and UR respectively. These cells may be of selenium construction but are preferably light responsive cells of the photoelectric type. The cell LCI is shown included in a circuit which may betraced from the terminal of a suitable source of current, slip ring 40, through cell LCI, winding of the down relay DR, and back contact 49 of the up relay UR, to the terminal It is of course understood that in practice suitable amplifying means, not shown, may be employed to amplify the current produced by the photo-electric cell. A similar circuit for the relay UR may be traced from the terminal slip ring 40, through the light responsive cell L02, winding of the relay UR, and back contact 50 of the relay DR to the terminal These relays DR and UR are provided with contacts 5|, 52, 53 and 54 which for obvious reasons will cause current of one polarity or the other to be applied to the motor M of the permanent magnet field type or induction type, the polarity depending upon which of the two relays DR or UR assumes its energized condition.

It will be observed that the relay DR may be picked up by depression of the push button contact PD, whereas the relay UR may be picked up by depression of the push button contact PU. These push button contacts are provided for test purposes and should not be used during route flying. It will be observed (see Fig. 2A) that the motor M (also shown in Fig. 2C) is operatively :are provided (see Fig.1) anisms are driven'through gear mechanism so as to rotate only one complete revolution for two,

aeoaesi connected to the gear 42 rigid with rim- 48 wise rotation of the rim 48 (as viewed from the right in Fig. 2A) to cause the two light respon sive acells LCI andLC2 to again assume pos1- tions on oppositesides of the light beam in its new location. 1 In other words,;the lightrespon- 20,000 feet. In otherwords, the pilot must be relied upon to properly lread and interpret the altimeter includingthe pointer 45. In order to provide contacts which complete -a different circuit for each altitude between 1000 feet and 20,000 feet, contact arms 20, 2|, Hand 24, of which the contact arm 2| only has been shown, These contact mechcomplete revolutions of the pointer 45. This gear reduction is provided through the medium of the gears 42 and 51, the gear 5'! having twice the The contact arms, 20,122

diameter of gear 42. and 24 are also carried by the shaft 50 which carries the contact arm 2-l. arms 20, 2!, 22 and 24, the arm 2! is more specifically shown in Figs. 2A and ofthe draw ings. In order to provide an additional indicator which does not require interpretation by therefore be apparent that each airplane radiates rearwardly directed energy characteristic of the altitude at which the airplane .is flying and ended at a'rate to characterize the particular airplane. I V jl Q Also, the system of; the present invention has been designed so that the pilot of each airplane by looking upon the screen of his kinescope will see the way stations in advance of him on the screen and coded to manifest traffic conditions in advance for the particular altitude at'which heis flying. This is true because the altimeter contact mechanism in Figs. 2A, 2B and 20 will tune his radio receiver for the modulated frequency assigned to the particular altitude at which the airplane is flying, as shown by contacts 20 of the altimeter contactor AC (Fig. 1). The pilot is, however, provided with a hand knob HK (Fig. 1) and a push button'PB through the medium of which he maylook into another altitude so to speak by adl'usting this hand knob I-IK for such other altitude and by depressing the push button PB. Bylook intoi is meant-cause his kinescope'to' display .tra f itibns in Such other altitude. V v

' Let us now 'assumethat the pilot of airplane.

Of these Contact IPZ (Fig. 1) desires to change altitude because of another airplane IP4 (notshown), in advance thereof. Letus first assume that he turns his hand-knob HK to the 3 position and depresses his push button PB (Fig. 1) This operation will enable'the pilot of the airplane, IP2 toobserve an indication G-over-G-as shown for altitude 3 at fixes B and A, as shown in saidparentapplication. The pilot will of courseknow that it is unsafe for him to descend to altitude 3000 because he is informed by. this indication G-and -G that there is an airplane in the'3000 foot alti-- tude and in the same section'or block'in which he is flying.

Let us now assume that the pilot turns hishand-knob HK to the'5 positionan'd'then de-' presses the push button PB; He-will then observeaan indication of N-over'N signifying that he may ascend tojthej 5000. foot altitude with safety. This N-over-N' indication signifies no airplane at altitude 5000 inthe same section nor the section ahead or behind the section in which airplane IP2 is flying; Let usnow assume that he starts to climb with his airplane IP2 and as he almost reaches altitude 5000 his altimeter contact mechanism AC will manifest the 5000 foot altitude and will not only through the mes dium of its contact 20' cause his screen 8 to display traflic conditions in altitude 5000 butwill also cause the tail; energy emitted by his airplane lPZ to be modulat'edto the 5000 foot' altitude modulating frequency. While the pilot'of airplane IP2 was making this ascent he would be expected to continue to keep. his push button depressed with his hand-knob HK on the 5 posi-.

tion, this by reason of the fact that traffic cone dlt ons might change in the 5000 foot altitude while he is making the ascent. If we assume that a change of trafiic condition didtake place before his altimeter indicated the 5000 foot altitude, the pilot being informed as to theindication displayed by his contact making altimeter, he would of course'know that'this change in indication from N-over-N to some other indication was due to another airplane if'his contact making altimeter has not yet manifested'ja 5000 foot altitude.

The applicants have thus disclosed a cab signalling system including airplane carried apparatus having a contact mechanism controlled in accordance with the altitude at which the aira desired indications both plane is flying and this contact mechanism is effective to govern both the received signals and the transmitted signals so as to cooperate with suitable ground located apparatus to provide the in the airplaneand on the ground. Although one particular structure of contact mechanism has been shown hereinrit should be understood that various changes, modifications, and additions may be made to, adapt 'the invention to the particular problem encountered in practicing theinvention without departing from the spirit orscope of the invention except as demanded by the scope-of the following claims.

What we claim is:

1. An altimeter device for operating contacts in accordance with altitude comprising," an

aneroid barometer including a fixed pointer 00- operating with a movable dial having a baro metric scaleQmanually operable means for mov-.

ing said dial to a position Where the pointer indlcates a given barometric pressure, a shaft turned by said barometer to different positions in accordance with the atmospheric pressure then acting on said barometer, a multiple position altitude contactor having two relatively movable contact elements, a follow-up system ineluding light responsive devices and operatively connecting said shaft with oneof said contact elements, and means directly connecting said dial and the other of said' contact elements, whereby a manual setting of the dial in accordance with the existing barometric pressure in a given region with respect to sea level will cause said multiple position contactor to take a position corresponding with the altitude location of the altimeter device 2. A contact making altimeter for airplanes comprising, an aneroid barometer including a movable pointer operated to different positions for varying atmospheric pressures, a fixed pointer, a movable dial adjacent said pointers, said dial having an altitude scale adjacent said movable pointer and a barometric scale adjacent said fixed pointer, a multiple position contactor having an adjustable contact carrying element with a plurality of fixed contacts mounted thereon for different preselected altitudes indicated on said altitude scale and also having a movable contact arm operative to co-act with said fixed contacts of said contact carrying element, a follow-up system including light sensitive devices governed by said barometer and a motor operatively connected to said movable contact arm to thereby effect operation of the contact arm to correspond with changes in air pressure, a manually operable means for adjusting said movable dial with respect to said fixed pointer, and a mechanical driving connection between said movable dial and said adjustable contact carrying element, whereby the operation of said manually operable adjusting means to set said dial wth respect to said fixed pointer to correspond to the existing barometric pressure in a given region with respect to sea level causes said movable pointer and said contact arm to assume positions corresponding with the altitude at which the airplane is then travelling.

3. A contact making altimeter for airplanes comprising, an aneroid barometer, a rotary shaft operated by-said barometer to different positions in accordance with the atmospheric pressure acting thereon as the altimeter is carried to different altitudes by the airplane, said shaft making more than one revolution for the range of altitudes the airplane may occupy in flight, a

multiple position rotary circuit controller having two relatively movable contact elements with a number of contacting positions corresponding to selected altitudes of said range of altitudes, a motor driven element, a follow-up system including light responsive devices and operatively connecting said shaft and motor driven element to cause said motor driven element to assume rotated positions corresponding with those of said shaft, a mechanical connection including the required reduction gearing between said motor driven element and one of the movable contact elements of said circuit controller to cause said circuit controller to assume diiferent contacting positions for the different altitudes of flight of the airplane for the same rotated positions of said shaft as it makes more than one revolution, and means for manually adjusting the position of the other of said movable contact elements in accordance with the existing barometric pressure in a given region with respect to sea level.

4. A contact making altimeter for airplanes comprising, an aneroid barometer, a rotary shaft operated by said barometer to different positions in accordance with varying;atmosphericpressure, said shaftrnakingmore'than one revolution for the range of altitudesthrough which the airplane may travel, a movable dial having abarometric scale adjacent a fixed: reference point and also having an altitudescale, a movable pointer mounted on said shaft and movable with respect to said altitude scale, a multiple position rotary circuit controller having a rotary contact element cooperating with an adjustable contact element, a motor driven element,a follow-up system includinglight responsive devices, saidsystem operatively connecting said shaft and said motor driven element to, cause said element to assume rotated positions corresponding with those of said shaft, a mechanical connection between said motor driven element and said: rotary contact element including reduction gearing of a particular ratio, manually operablemeans formoving said dial to a position to" conform with a given barometric pressure with respect to sea level, and a mechanical connection between said dial and said adjustable contact element having a reduction gear ratio corresponding to said particular ratio, whereby said movable dial and said adjustable contact element can be simultaneously set in accordance with changing atmospheric pressures with respect to sea level for a region although said shaft in making more than one revolution assumes the same rotated positions for different altitudes.

5. A contact making altimeter for airplanes comprising, an aneroid barometer, a shaft operated by said barometer to different positions in accordance with the atmospheric pressure acting thereon, a movable dial having a barometric scale and an altitude scale, a pointer on said shaft cooperating with said altitude scale, a multiple position circuit controller having a rotary contact element cooperating with an adjustable contact element carrying a contact for each of a plurality of different altitude positions of the rotary contact element, a follow-up system including light responsive devices and operatively connecting said shaft with said. rotary contact element, manually operable means moving said dial and said adjustable contact element simultaneously to positions to conform with a given barometric pressure with respect to sea level, and an indicating means including another altitude scale and another pointer connected with the respective contact elements of said circuit controller, said pointers and altitude scales enabling a comparison to be made between the contacting position of said circuit controller and the position of said shaft, and thereby determine whether or not said follow-up system has been eifective to operate said circuit controller in accordance with changes in altitude.

6. A contact making altimeter for airplanes comprising, an aneroid barometer, a rotary shaft operated by said barometer to different positions in accordance with the different atmospheric pressures as the altimeter is carried to different altitudes by the airplane, said shaft making more than one revolution for the range of altitudes through which the airplane may travel, a multiple position rotary circuit controller having two relatively movable contact members, a follow-up system including a motor operable in either direction, a driven element operated by said motor, two light responsive means mounted on said driven element, a mirror mounted on said rotary shaft and operated by said barometer to direct a ii a beam of light to one or the other of --said light responsive means in accordance withfthe direction of pressure changes, two 'rela'y's each respectively connected to one of said light'r'esponsive means, circuit means governed by said relays for operating said motorin one direction or the other depending uponwhich relay is then energizing-that relay, whereby sai'd circuit con- I troller can bemanually V operated to cause said contact element to assume a; position corresponding to the existing position of said'shaft.

/ I OSCAR S.

- SEDGWICK Nl WIGHT.

REFERENCES- GITED I The following references are ofrecord in the file orthis patentz' v Number j 1,234,170

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